ruby red gown by jason wu. this was the ball for the military. >> i have no greater honor than being your commander in chief. >> reporter: it had been an obama family day, malia and sasha, dad and mom. as america paid tribute. an inaugural parade that showed off the nation's talent and diversity. >> i, barack hussein obama, do solemnly swear -- >> reporter: the president's ceremonial swearing-in, witnessed by as many as a million people. >> so help me god. >> congratulations, mr. president. >> reporter: mr. obama urged cooperation, rare now in washington, to cut health care costs and the deficit. >> but we reject the belief that america must choose between caring for the generation that built this country and investing in the generation that will build its future. >> reporter: we can make progress, he said, on immigration, gay rights, climate change and school safety. a night to remember for the obamas and for the nation that re-elected the president. i'm steve handelsman, nbc news, washington. >>> president ob